The 28-year-old's
management announced said that Clijsters was diagnosed with the problem
- her second injury this season after another at the Australian Open -
following a loss in Miami to compatriot Yanina Wickmayer.

The injury was
defined as "a small torn muscle" in her right hip. The four-time major
winner is aiming to return to the sport in what she says is her final
season at the Madrid Masters starting May 5.

Clijsters, ranked
37th, has made the London Olympics her major goal for 2012 and has said
she then plans to retire. But she also refused to rule out playing at
the US Open - she has won it three times - which follows the London
Olympics by less than a month.

"The Olympics are
what I'm focused on now," said Clijsters in Miami. "This is the
long-term goal that I set when I started playing again (in 2009 after a
two-year absence to become a mother).

"But that doesn't
mean that I'm not going to play the US Open or anything. The Open is a
special place for me, you know, so I would definitely like to play
there, as well."